95Riv, FI,SC: Engine Problems began suddenly!

1995 Buick Riviera, 3.8 Fuel Injected, Super-Charged, 150K-miles
First of all, I am not a mechanic, I'm a 66 year old, unemployed programmer.
* Car had begun to suffer from oddities under acceleration for several months
during which time, fuel injection additive seemed to help.
* GARAGE installed new double-platinum plugs & both serpentine belts were installed
and the 95RIV ran 'great' for 7-weeks before the problem abruptly began
after an otherwise smooth 20 minute trip to the dentist.
When leaving 2 hours later, on start up the engine immediately had serious problems
which I thought were due to a defective tension idler pulley.
* Replaced both tension idler pulleys, with no improvement.
* Rough idle in park or neutral, but idle smoothes out above 1000rpm
* Under load, bogs down with no power and can't decide what gear to shift into...
but smoothed out going down hill or on the level.
* Super-charger pulley bearings make noise at slow idle.
* Intermittent Traction Control Light may simply be a loose 'ignition switch assembly'
that has been an issue since being replaced three years ago. (maybe a loose hard to get at connector)

FINALLY, here are the scanned codes and prices over the phone from a local parts house.
Codes Retrieved by Equus-3120 Scanner AZone retail prices
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po342-cam sensor $ 34.00
po112-IAT sensor chk $ 11.00
p1406-egr chk $ 128.00

Misc. Items
O2 Sensor $ 53.00
Mass Air Flow Sensor $ 85.00 (have not inspected it, but I did change it myself about 7 years ago)
THANK YOU for any help anyone can provide.
DKW (financially & mechanically challenged in Smyrna, GA) 20111002SU@0911AM

Could be the sensors, but I would start by looking at the vacuum lines under the hood to make sure they are not cracked or broken. Pretty cheap and simple fix that you can do yourself, if that's the issue.

Thanks! A friend of mine is coming over and we'll add that to the Inspection List. :-)

manofmany wrote:

Could be the sensors, but I would start by looking at the vacuum lines under the hood to make sure they are not cracked or broken. Pretty cheap and simple fix that you can do yourself, if that's the issue.

Do a search on this site for "vacuum" and related terms "vacuum lines" "replacing vacuum lines" and some such. There have been several posts about vac line replacement. Also - not all but many AutoZone stores will *give* you short lengths of fuel, vac and windshield washer small gauge hose as a business courtesy. They are not that expensive in the first place. You may be able to get a sales clerk or if you hit at the right time (not busy during the day) the commercial accounts manager (they are usually kinda knowledgeable) to go out with you to your car to reckon how much and what diameter hoses to get to replace all your under-hood vac hoses.

Albertj